Alto Neuroscience Advances ALTO-207 into Phase 2b for Treatment-Resistant Depression
Event summary
- Alto Neuroscience initiates Phase 2b trial for ALTO-207 in treatment-resistant depression (TRD), aiming to replicate positive PAX-D study results.
- Trial will enroll approximately 178 adults with TRD across the U.S. and U.K., including NHS sites from the PAX-D study.
- ALTO-207 combines pramipexole and ondansetron in a modified-release formulation to improve tolerability and efficacy.
- Topline data expected in the second half of 2027, with the trial designed like a registrational study.
The big picture
Alto Neuroscience is betting on ALTO-207 to address a significant unmet need in treatment-resistant depression, where current therapies often fail. The Phase 2b trial leverages prior positive data from the PAX-D study and aims to differentiate ALTO-207 through improved tolerability. Success could position Alto as a key player in precision psychiatry, particularly if the drug demonstrates sustained efficacy in larger trials.
What we're watching
- Clinical Efficacy
- Whether ALTO-207 can replicate the Cohen’s d effect size of 0.87 observed in the PAX-D study, positioning it as a potential breakthrough for TRD.
- Tolerability Profile
- The extent to which the modified-release formulation mitigates pramipexole-associated nausea and improves patient adherence.
- Regulatory Pathway
- How quickly Alto can advance ALTO-207 through subsequent phases, given the streamlined trial design aimed at supporting registration.